To display PDF files inside the Firefox browser window, you can use the built-in PDF Viewer or a PDF reader plugin. This article covers both methods and how to fix the common issues you might encounter.

To display PDF files inside the Firefox browser window, you can use the PDF Viewer extension or a PDF reader plugin. This article covers both methods and how to fix the common issues you might encounter.

Using the built-in PDF Viewer

Firefox now includes a built-in PDF viewer that allows you to view almost all PDF files found on the web without a plugin. The built-in PDF viewer is enabled by default.

Using the PDF Viewer extension

PDF Viewer (aka pdf.js) is a new revolutionary extension using web standard technologies that allows you to display within Firefox almost all PDF files found on the web without a plugin.

If you've installed a PDF reader plugin like Adobe Reader, you'll have to disable it (and any other PDF reader plugins) before the PDF viewer extension will work.

At the top of the Firefox window, click on the Firefox buttonOn the menu bar, click on the Tools menuAt the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.Click the menu button
and choose Add-ons. The Add-ons Manager tab will open.

In the Add-ons Manager tab, select the Plugins panel.

Select each PDF reader plugin and click Disable close to it.

PDF Viewer toolbar functions

View document thumbnails or outline - The slider button on the far left will open a sidebar with thumbnails of the document's pages. Some documents will also have an outline view available. These make it easy to navigate through a long document.

Page up and down or skip directly to a page - You can use the up and down arrows to page through a document or enter the number of the page you want to go to.

Change the size of the document - Use the + and - buttons to zoom in and out or choose a zoom setting from the dropdown menu.

Fullscreen or Presentation mode - Click the fullscreen button to allow the PDF file to take over your entire screen. Press ESC to exit fullscreen mode.

Print - Click the Printer button to open the print setup dialog.

Download - Click the Download button to save the PDF file to your computer or to open it with a PDF reader program.

Copy current view - Right-clickHold down the Ctrl key while you click
the current view button to open the current view in another tab or window.

PDF Viewer keyboard shortcuts

Command

Shortcut

Next page

N or K or →

Previous page

P or J or ←

Zoom in

Ctrl + +command + +

Zoom out

Ctrl + -command + -

Automatic Zoom

Ctrl + 0command + 0

Rotate the document clockwise

R

Rotate counterclockwise

Shift + R

Troubleshoot problems with the PDF viewer

Some PDF files don't render well or are blank

With certain types of PDF files, the PDF Viewer may have problems displaying fonts, colors or the whole document. To view these files:

Click the download button on the right side of the document header in order to open it with the default PDF program on your computer.

Cannot open any PDF files

Some extensions that block JavaScript may prevent PDF Viewer from working. You can disable them to allow PDF viewer to work:

At the top of the Firefox window, click on the Firefox buttonOn the menu bar, click on the Tools menuAt the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.Click the menu button
and choose Add-ons. The Add-ons Manager tab will open.

To change from using the built-in PDF viewer to your PDF reader plugin:

At the top of the Firefox window, click on the Firefox button and then select Options.At the top of the Firefox window, click on the Tools menu and then select Options.On the menu bar, click on the Firefox menu and select Preferences....At the top of the Firefox window, click on the Edit menu and select Preferences.

Click the menu button
and choose Options.Preferences.

Select the Applications panel.

Find Portable Document Format (PDF) in the list and click on it to select it.

Click on the drop-down arrow in the Action column for the above entry and select Use PDF reader name (in Firefox).

If PDF files are downloaded instead of displayed, try these solutions

If PDF files are downloaded instead of displayed, check your settings

At the top of the Firefox window, click on the Firefox button and then select Options.At the top of the Firefox window, click on the Tools menu and then select Options.On the menu bar, click on the Firefox menu and select Preferences....At the top of the Firefox window, click on the Edit menu and select Preferences.

Click the menu button
and choose Options.Preferences.

Select the Applications panel.

Find Adobe Acrobat Document (if you're using Adobe Reader) or PDF files(for other PDF readers) in the list and click on it to select it.

Click on the drop-down arrow in the Action column for the above entry and select Use PDF reader name (in Firefox).

If Use PDF reader name (in Firefox) is not listed as an Option, see Reset download actions below and then repeat this set of instructions.

Click OK to close the Options window.Click Close to close the Preferences window.Close the Preferences window.

Additional solutions

Reset download actions

Open your profile folder:

At the top of the Firefox window, click on the Firefox button, go over to the Help menuOn the menu bar, click on the Help menuAt the top of the Firefox window, click on the Help menu and select Troubleshooting Information. The Troubleshooting Information tab will open.Click the menu button
, click help
and select Troubleshooting Information. The Troubleshooting Information tab will open.

Under the Application Basics section, click on Show FolderShow in FinderOpen Directory. A window with your profile filesfolder will open.

At the top of the Firefox window, click on the Firefox button and then select ExitAt the top of the Firefox window, click on the File menu and then select ExitOn the menu bar, click on the Firefox menu and select Quit FirefoxAt the top of the Firefox window, click on the File menu and select Quit